Background: Hospital staffs, especially the nurses who have direct contact with patients and body substances are at higher risk of occupational hazards. Objectives: To assess the knowledge and practice regarding post exposure prophylaxis of HIV among the nurses and to find out association between Knowledge and selected demographic variables. Methodology: The study was conducted among the nurses working in medical–surgical units of MLBMC. 80 Nurses working in medical and surgical units were selected by stratified random sampling technique. Data were collected by using semi structured questionnaire. Chi–square was used to find out association. Result: Majority of the respondents fall in the group of 20–25 years, mean age=24.28, 81.2 % were staff nurses. Regarding the knowledge about PEP, 87.5 % knew the meaning of post exposure prophylaxis of HIV. 81.2 % had the knowledge regarding the first aid for an occupational exposure. Conclusion: Knowledge regarding PEP was found to be satisfactory in majority of respondents but practice was found to be less.